This uses "foreach" in order to create proper dependencies for each
cubemap face and miplevel.
It also adds a custom command for the mesh and envmap assets, similar to
how we already handle materials. This seems to work properly and
rebuilds the assets only when upstream dependencies have been dirtied,
or when downstream dependencies have been deleted.
* Introduce two WebGL samples: triangle and suzanne.
This commit has no effect on mobile / desktop builds, it only adds new
targets to the `-p webgl` build.
We will eventually expose a proper JavaScript API, but for now these
samples use a (somewhat under-engineered) `filaweb` framework whereby
the WebAssembly module exposes a small number of C entry points: launch,
render, and resize.
Each sample has two source files: a cpp file and an html file. The cpp
file generates js / wasm pair. The generated js is simply a loader for
the wasm.
The CMake script creates a pristine "public" folder which contains the
minimal set of files needed to serve the web application using a simple
static file server. The public folder like this:
/suzanne.js built by em++ from suzanne.cpp
/suzanne.wasm built by em++ from suzanne.cpp
/suzanne.html copied from REPO/samples/web
/filaweb.js copied from REPO/samples/web
/favicon.png copied from REPO/samples/web
/monkey/*.png copied from REPO/assets/models
/monkey/*.filamesh built by filamesh
/desert/* built by cmgen
To decode PNG textures, we use the somewhat unusual approach of using
JavaScript to draw them into a hidden 2D canvas, then reading back the
pixels. This allows us to avoid fattening up the wasm file with a PNG
decoder. An alternative idea would be to pass a DOM Image directly into
glTexImage2D, but this would require some #ifdefing and/or JS injection
in Filament's OpenGL backend.
* Optimize the suzanne material.
